1.   It was clear that, in the early stages of embryo development, the cytoplasm is in the driving seat.

2.   As a result, the researchers concluded that as cells developed, the proteins coating the DNA somehow masked all the important genes for embryo development.

3.   Before delivering the embryos to Harvard, the Boston IVF staff must prepare them, creating an opportunity to study embryo development, Powers said.

4.   One theory is that the build-up of man-made chemicals in the environment -- many of which can mimic female hormones -- could be interfering with male embryo development.

5.   Schatten hired Dominko and several other experts in embryo development to do the work.

6.   That is because in normal embryo development, certain genes from the father but not the mother, or vice versa, are turned on.

7.   That was made possible by advances in medical therapies as well as in laboratory techniques for supporting embryo development, said Dr. Thomas Toth, director of the program.

8.   Americans Edward B. Lewis and Eric F. Wieschaus and German Christiane Nuesslein-Volhard won the Nobel Prize for medicine for studies of how genes control early embryo development.